Methyl Ethyl Ketone → Ethyl (5-bromobenzofuran)-2-carboxylate

HRID 902017

Reaction equation

HRID 902017 reaction equation
[Br:1][C:2]1[CH:9]=[C:6]([CH:7]=O)[C:5]([OH:10])=[CH:4][CH:3]=1.C([C:13](CC)([C:18]([O-:20])=[O:19])C(OBr)=O)C.C(=O)([O-])[O-].[K+].[K+].[CH2:29](C(C)=O)[CH3:30]>>[CH2:29]([O:20][C:18]([C:13]1[O:10][C:5]2[CH:4]=[CH:3][C:2]([Br:1])=[CH:9][C:6]=2[CH:7]=1)=[O:19])[CH3:30]

Participants

5

Reactant 4

HCID 6569Methyl Ethyl KetoneHCID 11430Potassium CarbonateHCID 728635-BromosalicylaldehydeHCID 86590788Bromo diethylmalonate

Product 1

HCID 735184Ethyl (5-bromobenzofuran)-2-carboxylateYield 78%

Procedure

A solution of 5-bromo-salicylaldehyde (5.0 g, 25 mmol) and bromo diethylmalonate (8.9 g, 37 mmol) in methyl ethyl ketone (50 mL) is treated with potassium carbonate (6.8 g, 50 mmol) and heated to reflux. The reaction is stirred over 3 days at reflux. The reaction is then concentrated to a crude solid that is purified by silica gel column chromatography (9:1 hexane/EtOAc) to afford 5.2 g (78%) of the desired product. 1H NMR (CDCl3) 7.81 (d, 1H), 7.26-7.55 (m, 3H), 4.44 (q, 2H), 1.42 (t, 3H).

Workup

  1. temperatureheated to reflux
  2. temperatureat reflux
  3. concentrationThe reaction is then concentrated to a crude solid
  4. customthat is purified by silica gel column chromatography (9:1 hexane/EtOAc)

Sources & evidence

ORD record
ord-dcd1e3fcb5a746e995bd0fae885d2464
Source dataset
uspto-grants-2008_04
Patent number
US07365066B2

Linked notes

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